FIG. 1 is a schematic architectural diagram of an existing cellular network, and as illustrated, in the existing cellular system, a terminal determines a serving base station according to the strength of a downlink pilot signal, and the serving base station is responsible for providing the accessing terminal with a data transmission service. The serving base station forwards uplink data received from the terminal to a core network. The core network is responsible for verifying the identity of the terminal, storing context information of the terminal, and providing the accessing terminal with a connectivity service to an external network.
In the related art, the terminal is registered with the network in an Attach procedure. While the terminal is being registered with the network, a Mobility Management Entity (MME) of the core network is responsible for storing state information of the terminal, including security context information, activated session information, positional area information, etc. The state information of the terminal is stored in the core network, so if the accessing terminal is a machine-type terminal, then there may be two problems as follows.
Firstly the number of machine-type terminals is expected to go far beyond the number of existing terminals (up to the level of possibly 50 to 100 billions as anticipated), so if a complete context is created in the core network for each machine-type terminal, then there may be an unacceptable storage burden for the core network; and secondly the core network is also involved in a connectivity management function of the existing terminal, and this means that a lot of signaling in the core network may be produced each time when the terminal becomes connected, so if a large number of machine-type terminals access the network, there may be easily a storm of signaling.